Wideband 02 Issues?

[Blown98RT]

After reading previous posts...it is my understanding that UEGOS(V) should stabilize to ~0.45V after 30-40seconds of idle time.

With my engine running, after several minutes of idle time, the my wideband readings are this:

UEGOR(V)~2.37
UEGOS(V)~0.61 (sometimes lower sometims as high as 0.7x)
UEGO(V)~.002

With the Key on/engine off

UEGOR(V)~2.37
UEGOS(V)~0.20
UEGO(V)~4.98

With the sensor unplugged and engine on

UEGOR(V)~4.98
UEGOS(V)~1.00
UEGO(V)~3.53

Are these figures normal?

Often my a/f at idle after warm up will be extreme, either 9.19 or 15.94. I have never been able to get a steady 14.x or so a/f ratio at idle. My VE is about 39 or 40 at idle with no after start correction. I do see 02 correction on WOT pulls but I want to confirm the health of my 02 before I put a bow around the tunning of the driveability and WOT aspects of this thing.

Thanks for the help!

 

[Blown98RT]

Craig, Lance, anyone? Thanks

 

[Craig Smith]

From here, my first thought is that this sensor is failing. Was this working OK previously?

 

[Blown98RT]

The readings have always been flaky with the O2 sensor. I have never been able to get a consistant a/f ratio at idle. I do see correction through the power band, but i'm not sure how reliable it is. There is a little history though that should be mentioned:

I had some problems with my FastTrack harness and network box when I first got the FAST unit. It took me a while to realize that I was not getting O2 correction. After some work on the phone with Mac and the voltmeter, I sent the unit back to FastTrack and "a cold solder was fixed" on the wideband heater wire circuit (in the network box). I was only getting low 10.x volts, when 12-13 was required. I was also sent a new wideband extension cable. Fasttrack fixed the heater wire issues, but shortly after the truck went under the knife for motor work. The truck sat for over a year and I'm just know getting it back in the tuning mode. So, I can't confirm 100% if the wideband worked 100% after that point. I can say that I did get O2 correction through the power band after this fixed, but I still could not get the consistant a/f ratio at idle. I fear that perhaps the O2 was damaged if the heater wire wasn't working correctly and I'm just now realizing this.

The last time I removed the O2 sensor it did look like it was pretty black. I assume carbon buildup can cause this sort of failure? Any suggestions to research...any other voltages to check, etc would be appreciated.

Thanks

 

[Craig Smith]

Consistent readings at idle will be the toughest thing to rely on in a performance engine. A lot of people seem to do OK with this, but it is not uncommon to see inaccurate a/f readings at low engine speeds when big exhausts and camshafts are involved. If things seemed to be OK during WOT runs then things were likely working properly after the wiring changes you made with Mac.

Carbon fouling and oil fouling are the two biggest O2 killers we see.

 

[Blown98RT]

Should I still be concerned with the fact that the UEGOS(V) is not stabilizing to ~.45? If Carbon fouling is the culprit (from how black the O2 is, this seems highly likely), is there a way to "clean" it besides running the engine leaner? Perhaps a "sensor-safe" cleaning solution? Perhaps the sensor is just getting skewed readings and not permantelly damaged yet. Obviously I don't want to buy another pricey wideband considering this unit has less than 500 miles on it. However, if necessary I will. I would just like to rule out all possibilities first.

Would it help if I send a data log file to you charting UEGOS(V),
UEGO(V) and UEGOR(V) to evaluate the O2 health and correction further?

Many thanks Craig!

 

[No Quarter]

I was experiencing similar issues along with interrupted O2 readings. It turned out there was some moisture in the connection housing off the sensor. I blew it out with a can of compressed air. I wouldn’t use an air compressor since you can sometimes get oils and moisture in the tank. I then used a bit of contact cleaner on the connections and it reads fine now.

Just an idea.